Investigators believe dairy farmers added a dangerous chemical to milk that has been linked to kidney stones in dozens of babies and one death in China’s latest product safety scandal.

The government vowed “serious punishment” on Friday after China’s biggest milk powder producer recalled 700 tons of baby formula. The official Xinhua News Agency said the powder was tainted with melamine, a toxic chemical used in plastics that contaminated pet food last year.

U.S. authorities warned American consumers to avoid all Chinese infant formula. Although Chinese formula is not approved for import into the United States, it might be sold at ethnic grocery stores, the Food and Drug Administration said.

A New Zealand company that owns a stake in the Chinese producer said it believed none of the powder was exported from China.

The producer, Sanlu Group, knew about the contamination Aug. 6 but refrained from telling the public, said a company manager, Su Changsheng, quoted on the Web site of Caijing, a leading Chinese business magazine. Su said Sanlu kept silent because some grocers refused to return tainted powder.

A separate Xinhua report said investigators believed dairy farmers were to blame. People who answered the phone at Sanlu said managers were not available to comment.

Authorities are questioning 78 people suspected in the contamination, Xinhua said.

“The suspects added water to the milk they sold to Sanlu to make more money,” Xinhua said, citing deputy mayor Zhao Xinchao of Shijiazhuang, the city where Sanlu is based. “They also added melamine so that the diluted milk could still meet standards.”

'Serious punishment'
Su, the Sanlu manager, said the chemical might have been added to make the milk’s protein content appear higher, according to Caijing. Melamine is nitrogen-rich, and standard tests for protein in bulk food ingredients measure levels of nitrogen.

“Those responsible will face serious punishment,” said a Health Ministry spokesman, Mao Qunan, quoted by Xinhua.

The tainted formula sent 59 babies in northwest China’s Gansu province — most less than a year old — to the hospital and one baby died, Xinhua reported. Other cases were also being reported across the country.

Investigators found melamine in the urine and kidney stones of the sick babies, Xinhua said, citing a government investigation team.

Lu Yuan, a urologist with the No. 1 Hospital of the Chinese People’s Liberation Army, told Xinhua that 14 sick babies were brought into her facility in Lanzhou, capital of Gansu province.

“Most of the babies looked worn-out and had a fever when they arrived at the hospital. Some didn’t produce any urine for two to three days and were in very serious condition,” she was quoted as saying. She said eight babies remained hospitalized, while six had been treated and released.

It was the second prominent case involving harmful baby formula in China in recent years. In 2004, more than 200 Chinese infants suffered malnutrition and at least 12 died after being fed phony formula that contained no nutrients. Some 40 companies were found to be making phony formula and 47 people were arrested.

The reputation of Chinese exports was battered last year by deaths and injuries blamed on tainted toothpaste and other products. The incidents damaged faith abroad in Chinese goods and sparked an overhaul of its regulatory system.

Sanlu has 18 percent of China’s market for milk powder, according to government data. The company says it produces 6,800 tons of milk a day and buys milk from suppliers that include 60,000 farming households.

Sanlu became the dairy supplier to China’s space program in June and might provide milk for astronauts on the country’s upcoming third manned space flight.

The Health Ministry said Friday it was launching a nationwide investigation. It told local officials to report all possible cases and said it is “is urgently organizing experts to conduct research and treatment.”

The milk powder is sold in China under the name Sanlu Bei Bei Infant Powder.

“We understand that the product involved is only sold in China,” Fonterra Co-operative Group, a New Zealand dairy farmers’ group that owns 43 percent of Sanlu, said in a statement e-mailed to The Associated Press.

中国最近的食品安全丑闻造成了一名婴幼儿死亡，多名婴幼儿患上了肾结石。调查人员认为，造成这些结果的原因是牛奶场的农民违规向牛奶中违规添加了危险的化学物质。

星期五，在中国最大的奶粉生产商宣布召回700吨含有有毒物质的婴幼儿奶粉后，中国政府宣称将对此事做出严厉的处罚。官方新华社的报道称：这些奶粉中被查出含有三聚氰胺。这是一种用于塑料生产的有毒化学物质。去年，这种物质曾被发现用于宠物饲料中。

美国政府告诫美国消费者避免使用所有中国生产的婴幼儿食品。食物和药品管理局宣称，虽然中国生产的婴幼儿食品在美国未获得进口许可，但在少数中国移民密集的城市食品杂货店里中仍有销售。

具一家持有该奶粉公司股份的新西兰公司称，这些奶粉绝对没有从中国出口过。

在中国领军商业杂志《财经》的网站上，“三鹿公司”的经理苏长深表示，其公司在8月6号就知道奶粉可能受到了污染，但一直未向公众透漏事件的真相。他说，保持沉默的主要原因是一些经销商拒绝回收这些被污染的奶粉。

另一则新华社的报道称，调查人员认为奶农应对此事件负责。但在电话采访三鹿公司的经理层时，工作人员却以不方便做任何评论拒绝。

新华社称，警方正在对此次事件的78名嫌疑人员进行传唤调查。

“嫌疑人为了赚取更大的利润，便向原奶中加水后卖给三鹿公司。”新华社援引石家庄市副市长赵新朝的话说。“他们为了使冲淡后的鲜奶符合收购要求，便向奶中加入了三聚氰胺。”

“严厉惩处”

具苏长深在《财经》杂志透露，奶制品的蛋白质含量目前依靠检测氮含量，奶农向鲜奶中添加三聚氰胺来提高氮含量。

新华社援引卫生部发言人毛群安的话说：“将严处毒奶粉事件的责任人。”

新华社称，这些受污染的奶粉造成了中国西北部甘肃省的59名婴幼儿入院治疗，大多数都不满一岁，其中还造成了一名婴儿死亡。在全国其它地方同样还有毒奶粉事件的报告。

中国人民解放军第一医院泌尿科医师卢元告诉新华社记者，14名患儿被送到了其在甘肃省兰州市所的医院。

“大多数小孩到医院时都是精神萎靡，而且还发高烧。有一些有两三天没有小便，情况很严重。”他说，其中6名婴儿已经康复出院，另外8名还在继续治疗当中。

这是中国近年来第二次比较有影响的婴幼儿食品含毒事件。在2004年，200多名中国婴幼儿因为食用了假冒的不含任何营养成分的奶粉而营养不良，其中至少造成12人死亡。有40家公司涉嫌生产假冒伪劣婴幼儿食品。47人被逮捕。

中国出口产品的名声早在去年就因为被指责出口受污染的牙膏和其它产品而败坏。该事件损毁了中国产品在国外的信誉度，同时也掀起了其对食品生产系统的彻底检查。

政府数据显示，三鹿拥有中国奶粉销售市场的18%的市场份额。公司称其每天的生产能力是6800吨。鲜奶主要从供应商处购买，这其中还包括60，000家奶农。

三鹿在六月份成为了中国航天航天乳饮料及乳粉的专业生产企业。而且可能在中国即将发射的第三艘载人航天飞船时为航天员提够专用饮用奶。

卫生部已组织联合调查组开展该事件的调查处理，并在全国范围内对可能由此造成的婴幼儿患病情况进行全面调查，同时紧急组织专家研究制定了诊疗方案。

这种含毒奶粉是以“三鹿贝贝婴幼儿奶粉”的名称在中国销售的 。

据悉，拥有三鹿43%股份的控股企业，新西兰恒天然集团在给美联社的一封邮件里提到：“所有这些有问题的产品都仅仅在中国境内销售。”